Controlling flow of precursors and other reagents into deposition chambers can be challenging, particularly when the precursors and reagents can easily react with each other and when multiple different precursors and reagents are needed to be supplied into the same deposition chamber. In a typical deposition apparatus, multiple lines for supplying different precursors and reagents are connected to a showerhead or another type of distribution device disposed within a deposition chamber. Each line may include multiple valves for introducing precursors and carrier gases into the line and purging the line. Furthermore, the line includes one valve connecting this line to the showerhead and controlling the flow of the precursors and reagents from the line and into the showerhead. This valve may be referred to as a “final valve” as there are typically no more downstream valves. The final valve needs to be positioned as close as possible to the showerhead to avoid “dead volume” issues.
A typical deposition apparatus includes externally controlled valves, which are connected to a system controller for controlling these valves. Specifically, externally controlled valves typically use electrical or electromagnetic actuators to move flow restrictors and other such components. The actuators also connected to the system controller by signal and/or power lines. Overall, the externally controlled valves are bulky and not temperature resistant. As such, when externally controlled valves are used, these valves cannot be positioned close to the showerhead because of the heat and access reasons. At the same time, many deposition processes are performed at high temperatures that cause heating of the showerheads, walls of the deposition chambers, and other components positioned close to the deposition chambers, which include final valves. Furthermore, many new deposition approaches, such as high productivity combinatorial (HPC) processing require many different supply lines connected to the same showerhead, which complicates positioning and maintenance of the valves. At the same time, moving the final valves away from the showerhead increases dead volumes and negatively impacts operation of these apparatuses.